Peter Guttman/Corbis

By the end of this decade we will know how harshly history will judge us. If we want to spare our descendants the worst effects of global warming, the world’s emissions of greenhouse gases will have to peak before 2020 and start declining thereafter. Tragically, we’re almost certain to miss that fateful deadline. At the December 2009 United Nations climate conference in Copenhagen, delegates from 192 nations failed to produce any legally binding agreement to reduce emissions. Blinded by ideology, willful ignorance, or perhaps simple selfishness, we’re tumbling headlong into a new era. Paul Crutzen, a Nobel laureate at the Max Planck Institute for Chemistry in Mainz, Germany, calls it the Anthropocene, from the Greek words for "man" and "recent," to reflect the epochal impact human activities now have on the earth’s climate. So perhaps it’s a sign of the times when books start to appear that focus not on preventing or minimizing global warming but on how civilization might adapt to temperatures that probably have not existed on the planet for millennia.

In The World in 2050, Laurence Smith, a professor of earth and space sciences at the University of California, Los Angeles, has written an informed, readable, and important account of where current trends will most likely lead us. Overall, the future he describes is not a happy one. The world’s poorest cities, particularly those of sub-Saharan Africa, will become more crowded, more desperate, and more dangerously unstable. Droughts like the one that cost California roughly $500 million in lost agricultural revenue in 2009 alone may become the norm. But Smith also makes a credible case that, for a lucky few, global warming will not be all bad.

Smith devotes relatively few pages to the world as it might be in 2050; much of his book is actually a remarkably comprehensive report on the state of the world today. The unifying theme, though, is that countries bordering the Arctic will not only adapt to climate change but thrive, even as much of the rest of the world confronts water shortages, coastal flooding, mass human migrations, and other calamities. The Arctic, measurements show, is heating up twice as fast as the rest of the globe: sunlight that ice once reflected back into space now gets absorbed by ever larger tracts of open ocean and exposed land. This meltdown will make it easier to access the Arctic’s vast natural resources, including some of the very fuels that stoke global warming. The U.S. Geological Survey estimates that 30 percent of the world’s remaining natural gas and 13 percent of its untapped oil will be found in the Arctic. Chevron, ExxonMobil, and other companies have already snatched up drilling sites auctioned by the government of Greenland in waters where sea ice had until recently made the prospect of oil exploration all but impossible.

Eight nations, Smith argues, stand to benefit as the Arctic melts: the United States (thanks to Alaska), Canada, Russia, Denmark (because of close ties to its former colony, Greenland), Norway, Sweden, Finland, and Iceland. These northern rim countries, or NORCs, as Smith calls them, will see an influx of investment; their long winters will become more tolerable, their water reserves more valuable; humans, plants, and animals will migrate north, seeking relief from the hot, crowded, water-stressed lower latitudes. Climate change won’t be the only factor driving the transformation. Smith includes three more forces in his short list of world-shapers: population growth, accelerating globalization, and humanity’s insatiable demand for natural resources.

World population is projected to hit 9.2 billion in 2050, in effect squeezing two more Chinas onto the planet. Three huge economies -- China, the United States, and India, with China being by far the largest -- will dominate the world, competing for  food, water, and energy. Although China and India won’t benefit from global warming, their economies will continue to grow, with per capita incomes in both countries likely to rise substantially. So will their energy consumption. Given that China today builds about two new coal-fired power plants every week -- equivalent to adding another United Kingdom to the global energy grid every year -- the prospects for a greener world 40 years from now look bleak indeed. In terms of where we get our energy, Smith writes, 2050 will look very much like 2010. We’ll still rely on coal, oil, and gas to supply most of our energy.

Our continued reliance on fossil fuels for much of this century means many of the problems we face today will persist for decades, one of the most urgent being how to avoid dumping all the carbon we’ll still be using into the atmosphere. The increasing use of coal to replace dwindling supplies of oil and natural gas will be especially problematic. Unfortunately, we’re not developing alternatives aggressively enough. Today, wind and solar combined supply barely 1 percent of the world’s electricity. Even with the greenest projections of future energy use, Smith writes, that contribution will increase at most to 30 percent in 2050. The United States will burn 40 percent more coal in 2050 than it does now; China’s consumption will double. Ultimately, the world economy will shift to renewable forms of energy (if for no other reason than all the oil, gas, and coal have gone up in smoke), but Smith sees no chance of that happening by 2050.

Advocates of "clean coal" technology -- and that includes President Barack Obama and other world leaders -- are betting heavily that a nascent technology will eventually make it possible to capture, liquefy, and store all that carbon underground before it leaves any smokestacks. But Smith argues incisively that carbon-capture technology, as it’s called, may never work, at least not on a scale where it would make much of a difference.

I wish every politician in the world would read at least these two sentences from this book: "The United States alone produces about 1.5 billion tons of CO₂ per year from coal-fired power plants. Capturing and storing just 60 percent of that means burying 20 million barrels of liquid per day [my italics] -- about the same as the country’s entire consumption of oil." Even if we managed to build the enormous infrastructure to store so much carbon, Smith writes, an annual leakage rate of just 1 percent would, within a century, result in the escape of nearly two-thirds of the stored carbon into the atmosphere. We, or our great-grandchildren, would be back where we started. Smith doesn’t offer any near-term solutions to this problem, and it seems we have no choice but to push on and do our best to develop carbon-capture schemes.

The climate models Smith relies on for his predictions are improving steadily, but for now scientists can only bracket our future between best- and worst-case outcomes. At the optimistic end of the range, by the end of this century temperatures in the United States, Europe, and China will average about 4.5 degrees Fahrenheit higher than today. The pessimistic models predict an increase of 9 degrees Fahrenheit.  As Smith emphasizes, that’s close to the increase we have experienced since the last ice age, 20,000 years ago.

All the models predict that the earth’s northern latitudes will change substantially. One of the consequences of global warming is that drier areas will tend to become even drier while the wet regions become wetter. At the northernmost latitudes, lakes and seas will remain unfrozen for more months of the year, so evaporation -- and precipitation -- will increase in the Arctic. It will be one of the few parts of the world to enjoy a water surplus. And access to clean water, in Smith’s opinion, will be the greatest challenge of the twenty-first century. It would remain a major problem even without climate change, he writes, because population growth and the spread of industrialization both place greater demands on water supplies than global warming does. Today, about 40 percent of the world’s population lack access even to simple latrines.

Despite the prospect of severe water shortages for much of the world’s population later in this century, Smith believes it’s unlikely that any nations will actually go to war over water. Water, he argues, is too important to fight over. No country wants to risk losing access to water; the incentive to cooperate outweighs any potential benefits of a water war. To support his argument, Smith points out that Egypt, Israel, Jordan, India, and Pakistan have all managed to avoid outright war when it comes to water. More probable than bloody conflicts, Smith suggests, will be the proliferation of enormous engineering projects to siphon northern water to the thirsty south. He says it’s very likely that long-dormant schemes, such as proposals to pump water from Canada’s James Bay watershed and to tap the rivers and lakes of Siberia, will shed their near-crackpot status and become viable political options. And of course, oil, gas, or coal would be needed to power the pumps...

So will oil and water mix in the Arctic, creating new wealth and opportunities in a region now inhabited mostly by Inuit, Sami, and other isolated native peoples? Is Smith’s optimism about the  north’s future justified? He points to the growing political independence of Greenland, which is ruled by its aboriginal population, the Greenlandic Inuit. In Canada, the Inuit of Nunavut, a territory about the size of Mexico, are the country’s fastest-growing population; already they’re collecting revenues from mining and oil companies. Smith believes the north will see more pipelines and ports, with oil, gas, and water flowing south and money north. "I see the original stewards of this land taking it back again," he writes.

Smith’s argument falters here. History does not contain many examples of indigenous peoples prospering when larger nations crave their resources. The Arctic future will likely play out in more complicated ways than Smith describes. In the summer of 2009, I spent three weeks in Greenland, meeting with politicians, scientists, farmers, hunters, and fishermen. Oil wealth is still a distant dream, and more than a few people I spoke with worried that an Arctic boom may create more problems than it solves. Minik Rosing, a native Greenlander and one of the world’s leading geologists, told me that large-scale development in the Arctic could overwhelm the Inuit and other native groups. Greenland, for example, has fewer than 60,000 people -- the entire population could fit in the Louisiana Superdome with thousands of seats to spare. Oil companies would  inevitably need to bring in trained workers and support staff from elsewhere, and Rosing fears the Inuit could become a minority in their own land. "We’d have this dilemma: Should we have a work force that lives and works here with no civil rights, or should we have a workforce that has rights but would be a majority in Greenland?" he said. "I’m not saying it could not be done, but it’s not a free ride."

Some wealth will no doubt come to the people of the Arctic, as Smith writes, but at what cost to them and the rest of the world? Will "the original stewards of the land" be stewards no more? Wealth derived from the continued extraction of fossil fuels hardly seems consistent with stewardship. Smith acknowledges that any profits wrung from global warming in the north will be paid for with immense human suffering elsewhere -- 2050 doesn’t hold much promise for the world’s poor and powerless.

The crisis posed by global warming, it seems, is in part a moral one: Can we in the developed world live with less? Is it preordained that our economies must expand the frontiers of globalization to the very highest latitudes on earth, regardless of cost? Cheap energy has made us wealthy, and maybe we can no longer afford to be so rich.